The BIG bang

[VermilionUK]

I've often found myself asked the question "so how did something come from nothing?"
I would usually answer "ok, so how did god come from nothing?"

So, I don't consider myself educated on this matter of the big bang or the beginning of the universe, but I've read across some points regarding chaos and particles spontaneuosly coming in and out of existence - and as such would like some dialogue regarding the first stages of the big bang.

Or, in simple terms:
Explain the chaos theory

Explain evidence behind it (yes, I know its only a "theory" and as such, probably lacks solid evidence - but so does God, yet theists cling to that)

Explain other possible/probable causes to the universe (if indeed it had a "cause")


Now, before we get "ha! You can't explain it - therefore God exists", we must also face the fact that there is no evidence of a creator (as far as I know). And of course, if the simple answer is "we don't know what happened" then it gives us no reason to assume it was some divine being.

[Defender of Truth]

ok, so how did god come from nothing?"

I'm sorry but I'm not familiar with the chaos theory, so I can't explain it to you.

And I apologize sincerely if I'm upsetting your thread, and I know it's not the point of your post, but I would like to most humbly insert the statement that nobody claims God came from nothing. We claim he's the noncontingent cause stated in the Principle of Contingency.

I apologize again if I'm throwing the thread off topic.

[GrumpyMrGruff]

Or, in simple terms:
Explain the chaos theory.

I'll outline chaos theory, but I'm not sure it means what you think it does.

First, some terminology:

• Dynamic system - A mathematically defined system that changes over time. These models can be physical (describing positions or other physical values), chemical (tracking concentrations of reacting chemicals), biological (tracking individuals in a population), economic (money), or just about any other phenomena.
• Deterministic systems follow fixed sets of rules without any random input. In an ideal world, if you know the starting positions of all the players in your model, you could predict their future and past values exactly.
• Stochastic (random) models incorporate an intentional element of randomness. This could be used to describe processes like isotope decay where we can only predict probabilistically when the next event will occur.

Chaos theory deals with deterministic systems. Many mathematical statements in physics, chemistry, and biology are deterministic. However, chaotic models are very sensitive to initial conditions. This means that a small change in the initial concentration of a reacting chemical or the position of an orbiting planet can have a large impact on the output of the model at a later time.

What this means empirically is that for certain systems in the real world, very small changes in starting conditions can translate to very different outcomes. These changes in initial conditions may be too small to measure, so it may appear to us that the same input gives very different outputs at random.

Take a look at this gravitational simulator from the University of Toronto. Set the number of planets to 4 at the lower right. What are you watching? The 4 planets do not interact with one another gravitationally. Rather, you are seeing 4 independent simulations with planets starting in slightly different positions. Watch for a few minutes and you will see that the small changes in initial position have a very large impact on the planets' later behavior - this is the essence of chaos theory.

Chaos theory is a field of study in mathematics (not natural science) - as such, the evidence for it consists of the mathematical models which exhibit chaotic behavior. Chaos theory is extended to natural sciences because some mathematical descriptions of natural processes exhibit chaotic behavior.

Your originally post describes virtual particles, which are (IIRC) a prediction of the math behind quantum physics but not observable by definition.

Regarding the Big Bang, I'd like to draw your attention back to deterministic systems. Ideally, if we could know the exact state of a system, we could extrapolate forward or backward in time. However, the singularity at the Big Bang causes all our physical models to break down. I am not a physicist, but it's my understanding that the Big Bang theory does not attempt to explain the ultimate origins of space/time or matter/energy. Rather, the Big Bang is set as time 0 because it is as far back in time as we can hope to "look." There is no way to extrapolate "before" the Big Bang (if there was a before) because our mathematical descriptions of the universe break down, preventing it. As such, the ultimate origins of the universe are unknown and may actually be unknowable. If I'm mistaken, I welcome correction. Physics wasn't my main field of study.

[VermilionUK]

Or, in simple terms:
Explain the chaos theory.

I'll outline chaos theory, but I'm not sure it means what you think it does.

First, some terminology:

• Dynamic system - A mathematically defined system that changes over time. These models can be physical (describing positions or other physical values), chemical (tracking concentrations of reacting chemicals), biological (tracking individuals in a population), economic (money), or just about any other phenomena.
• Deterministic systems follow fixed sets of rules without any random input. In an ideal world, if you know the starting positions of all the players in your model, you could predict their future and past values exactly.
• Stochastic (random) models incorporate an intentional element of randomness. This could be used to describe processes like isotope decay where we can only predict probabilistically when the next event will occur.

Chaos theory deals with deterministic systems. Many mathematical statements in physics, chemistry, and biology are deterministic. However, chaotic models are very sensitive to initial conditions. This means that a small change in the initial concentration of a reacting chemical or the position of an orbiting planet can have a large impact on the output of the model at a later time.

What this means empirically is that for certain systems in the real world, very small changes in starting conditions can translate to very different outcomes. These changes in initial conditions may be too small to measure, so it may appear to us that the same input gives very different outputs at random.

Take a look at this gravitational simulator from the University of Toronto. Set the number of planets to 4 at the lower right. What are you watching? The 4 planets do not interact with one another gravitationally. Rather, you are seeing 4 independent simulations with planets starting in slightly different positions. Watch for a few minutes and you will see that the small changes in initial position have a very large impact on the planets' later behavior - this is the essence of chaos theory.

Chaos theory is a field of study in mathematics (not natural science) - as such, the evidence for it consists of the mathematical models which exhibit chaotic behavior. Chaos theory is extended to natural sciences because some mathematical descriptions of natural processes exhibit chaotic behavior.

Your originally post describes virtual particles, which are (IIRC) a prediction of the math behind quantum physics but not observable by definition.

Regarding the Big Bang, I'd like to draw your attention back to deterministic systems. Ideally, if we could know the exact state of a system, we could extrapolate forward or backward in time. However, the singularity at the Big Bang causes all our physical models to break down. I am not a physicist, but it's my understanding that the Big Bang theory does not attempt to explain the ultimate origins of space/time or matter/energy. Rather, the Big Bang is set as time 0 because it is as far back in time as we can hope to "look." There is no way to extrapolate "before" the Big Bang (if there was a before) because our mathematical descriptions of the universe break down, preventing it. As such, the ultimate origins of the universe are unknown and may actually be unknowable. If I'm mistaken, I welcome correction. Physics wasn't my main field of study.

Well, a very well thought-out and understandable explanation. Thankyou

[Scotracer]

Regarding the Big Bang, I'd like to draw your attention back to deterministic systems. Ideally, if we could know the exact state of a system, we could extrapolate forward or backward in time. However, the singularity at the Big Bang causes all our physical models to break down. I am not a physicist, but it's my understanding that the Big Bang theory does not attempt to explain the ultimate origins of space/time or matter/energy. Rather, the Big Bang is set as time 0 because it is as far back in time as we can hope to "look." There is no way to extrapolate "before" the Big Bang (if there was a before) because our mathematical descriptions of the universe break down, preventing it. As such, the ultimate origins of the universe are unknown and may actually be unknowable. If I'm mistaken, I welcome correction. Physics wasn't my main field of study.

I have been saying this on here ever since the Big bang was mentioned so I hope it's correct! As Stephen Hawking said: "We assume it as T=0".

[Sir Rhetor]

The way I look at it is a relevant beginning of time. Because all particles were at one point at the time and were all equal, anything previous to that time would be considered to be irrelevant. Now, science does not attempt to explain what happened previous to the big bang, which is why people think nothing was before.

It is important to note, though, that it is not the beginning to time, and that it cannot be said that God created the big bang because there was time previous to it. This is why the Catholic Church accepts the big bang model, because it so closely models Biblical text. Now also keep in mind what happens when it is the opposite of what the Bible says (evolution).

[hackenslash]

An interesting topic, and one which I know a little about.

Firstly, to deal with the above assertion concerning virtual particles, they actually can be observed having an effect. When the Casimir effect is studied using quantum electro-dynamics, the behaviour of virtual particles (or zero-point energy) can be seen. Here's a pretty good wiki on this topic.

Now, as for the big bang, there are a few good models. One of them is described in this brilliant and amusing lecture by Lawrence Krauss.



Another model that is currently on the table for the instanitation of the cosmos is the Turok and Steinhardt 'brane-worlds' hypothesis.

This hypothesis is described in simple terms in this video:



The beauty of this model, and one of the reasons it's pretty well-regarded among cosmologists is that it makes testable predictions that will manifest in our universe. The LHC has some of these tests within its remit. I can provide pdf downloads for the relevant scientific papers for the latter model.

Ultimately, the answer is that, at the moment, we don't know what the cause is.

Now, just a few words about time:

It has often been asserted that time began at the big bang. This has not, however, been established. Several of the models for cosmic instantiation suggest that time is actually an underpinning dimension of the universe, somewhat akin to a spatial dimension through which we travel at the speed of light.

I posted an explanation of this on another forum, so I'll simply reproduce that explanation here, along with the experimental evidence of relativistic predictions concerning the nature of time:

Ok. If it is time that slows, what is time? How is this shown in these experiments?

Simple. Here's a rundown of the experiment, carried out in 1971.

Four caesium clocks, synced to a fifth at the Washington Observatory, were flown around the world on airliners in both direction. When they were brought back together, the travelling clocks were about 0.15 microseconds ahead. Now, since the rate of these clocks is fixed, the only conclusion is that the travelling clocks experienced a slower rate of time. This is trivial even at middle-world speed. This ramps up more and more the nearer you get to light speed, leading to the twins paradox (which isn't actually a paradox).

atleast not intuitively. Remember the quote? "If you think you understand quantum physics, it is clear evidence that you do not understand quantum physics."

And yet you can post this drivel on this forum, which relies on the principles of quantum mechanics, specifically quantum tunneling. Your computer wouldn't work without it. Nobody knows for certain why it works or how it works, but work it does.

The clock experiment also gives us some indication of the nature of time. The reason for this is pretty simple, once you look at it from the right perspective.

Imagine that you are in a car on a wide stretch of tarmac.



Apologies for the crudeness, I couldn't find the image I was looking for, so I quickly made it. We have two cars. Now, imagine that they both hit the start line at exactly the same time, and exactly the same speed. You can see that the lower car is going iun a straight line from start to finish. The upper car is taking a diagonal run from start to finish. The upper car will take slightly longer, because it's travelling through two dimensions at once, while the lower car is only travelling through one. In this model, travel through the second dimension takes away slightly from travel through the first dimension, so it takes lonfer to travel the same distance.

Now, if you think about time, as akin to a spatial dimension as I described in my earlier post, and think about this analogy, you can see how relativity deals with this. The maximum speed you can travel is the speed of light. If you think of time as like a spatial dimension through which you are travelling at the speed of light, you can see the issue clearly. This speed limit applies to ALL dimensions, which means that if you're travelling through one dimension at light speed, you must be standing still in another. So, when you travel through space, you are reducing the amount of travel through time. This is why time slows when you are in motion. It is also why photons don't age, because they move at light speed, meaning that their travel through time is nil.

I hope that helps you to understand.

ANyway, the idea that time began at the big bang relies on the conventional view of the big bang coming from a singularity. Since black hole cosmology, coupled with relativistic effects concerning time, and specifically the fact that time slows in the presence of a large mass, due to the equivalence of motion to being immersed in a gravitational field, predicts that time stops at the singularity, it has long been assumed that there was no time before the big bang. This, alongside the idea that, because we had no means of looking beyond the Planck time (10^-43) seconds after the bang), that time was meaningless before that time. However, the Turok and Steinhardt model actually removes the singularity, while other models treat the singularity differently. Bear in mind that a singularity has several definitions in physics. The first is the conventional 'black hole' singularity, or an area of infinite density and infinite curvature (a point). The second is a broader definition in which it is simply an event in which our understanding breaks down. The Turok model removes the singularity altogether, and suggests that what preceded the big bang is fully conversant with the physics we experience in our cosmic expansion.

So, in summary, we don't have all the answers yet, but we have some good ideas and, even if those ideas turn out to be wrong, the testing of them will provide some excellent ideas about what the final solution will look like.

[Jayhawker Soule]

..., I don't consider myself educated on this matter of the big bang or the beginning of the universe, but I've read across some points regarding chaos and particles spontaneuosly coming in and out of existence - and as such would like some dialogue regarding the first stages of the big bang.

Would you please cite your source(s). I am unaware of chaos theory being used to explain "particles spontaneuosly coming in and out of existence". It would also be both interesting and strange to see chaos theory applied to anything before 1 Planck time.

[VermilionUK]

..., I don't consider myself educated on this matter of the big bang or the beginning of the universe, but I've read across some points regarding chaos and particles spontaneuosly coming in and out of existence - and as such would like some dialogue regarding the first stages of the big bang.

Would you please cite your source(s). I am unaware of chaos theory being used to explain "particles spontaneuosly coming in and out of existence". It would also be both interesting and strange to see chaos theory applied to anything before 1 Planck time.

Woops, sorry for the late reply.

I didn't say that Chaos theory was used to explain "particles spontaneously coming into existence". When I said "I've read across some points regarding chaos and particles spontaneuosly coming in and out of existence" I was stating them as separate things. Hence the "and" in the sentence.

[maplethorpej]

I would just like to inject a few point about the Big Bang theory.

1) It asserts that there is a center of our universe.
2) It means that we are either still expanding or compressing.
3) Why do we state the Big Bang at T=0 instead of T= - to .
4) Doesn't the Big Bang theory indorse a continuous cycle of destruction and creation over billions of years?

Your thoughts?